Robert bragg



(N0 Model.) Y i R. BRAGG.

GRANK PIN.

,No. 572,491. Patented Dec. 1, 1896.

"um A UNITED STATES PATENT OFFICE.

ROBERT BRAGG, OF DAYTON, OHIO, ASSIGNOR OF THREE-FOUR'IHS TO WILLIAM F.CHAMBERLIN, S. SCOVEL CHAMBERLIN, AND IVILLARD D. CHAMBERLIN, OF SAMEPLACE.

oRANK-PIN.

SPECIFICATION forming part of Letters Patent No. 572,497', datedDecember 1, 1896.

Application filed April 20, 1896. Serial No. 588,347. (No model.)

To all whom it may concern: p

Be it known that I, ROBERT BEAGG, a subject of the Queen of GreatBritain, residing at Dayton, in the county of Montgomery, State of Ohio,have invented certain new and useful Improvements in Crank-Pins andMeans for Securing the Same in Place; and I do hereby declare thefollowing to be a full, clear, and exact description of the same,reference being had to the accompanying drawings, forming a part of thisspecification, and the letters of reference marked thereon.

Much difficulty has been experienced in removing and renewing Worn andbroken crankpins, particularly the crank-pins of locomotivedrive-wheels, owing to the fact that when said pins were secured inplace in the ordinary manner it necessitated the removal of .the entirewheel from the locomotive, the

heating of the same to loosen the pin, and the shrinking in of a newpin. The expense of such an operation is very great; and it is theobject of my present invention to provide a crank-pin and means forholding the same in place which will permit of the ready removal orinsertion of the pin while the wheels are in place and at the same timeafford a rigid structure which will withstand shock and wear of usage aswell if not better than the ordinary arrangement wherein the pins aresecured by shrinkage of the metal of the wheel on the same.

Referring to the accompanying drawings, Figure 1 is a vertical sectionthrough a portion of the drive-wheel of a locomotive, showing acrank-pin applied in accordance with my present invention. Fig. 2 is adetail, on

. an enlarged scale, of the crank-pin alone.

base I now form a conical aperture through the wheel or crank, as thecase may be, having its smallest diameter at the outer side of the wheelor crank, and in this conical aperture I fit sectional clamping-blocksmade conical on the outer surface to accurately fit the conicalaperture, which clamping-blocks are formed with a cylindrical centralbore, into which the end of the crank-pin is fitted and adapted to beclamped by forcing the blocks into the conical aperture, as will bereadily understood.

Referring to said drawings, the letter A indicates a section of thedrive-wheeL'and a the conical aperture formed therein at the properdistance from the axis or center of rotation to give the desiredleverage to the crank. Fitting in this conical aperture are preferablytwo clamping-blocks B B, made conical`on their outer surface and groundto accurately it the aperture. A cylindrical aperture b is formedthrough these clampingblocks, and when in place they should be soproportioned that a very narrow space will be left between them. Inother words, instead of being truly semicylindrical in cross-sectionthey are slightly less than semicylindrical,

and at their rear or larger ends they are preferably provided with acountersink or enlarged bore C, for a purpose which will presentlyappear.

The crank-pin at the outer end is formed in an ordinary manner With abearing D for the connecting-rod and collars CZ d for holding theconnecting-rod in position. The collar d is adapted to seat against theface of the drivewheel, or, if desired, to be recessed into the sameslightly, and projecting rearwardly from this collar is the shankportion D', which is adapted to be accurately fitted in and clamped bythe clamping-blocks B. rlhe extreme rear end of the shank on thecrank-pin is threaded for thc'reception of a locking-nut E and also forthe reception of the jam-nut E for preventing the loosening of thelocking-nut wh en the pin is subjected to strains or shock.

The nut or nuts applied to the rear` end of the shank of the crank-pinare adapted to seat into the recessAC in the clamping-blocks, and

when set up draw the collar d iirnily against the drive-wheel and tendto force the clamping-blocks farther into the conical recess, the resultof which action is that the shank of the crank-pin is clamped firmly andheld accurately in a centered position. The countersinking of the nutsovercomes any liability of the nuts striking any part of the machinery,and inl effect presents the saine appearance as a Wheel having acrank-pin applied in the ordinary Way.

As an additional precaution against the possible loosening1 of thejam-nut I provide it with a set-screw F at one side adapted to passthrough the nut and cooperate with the threads on the shank of thecrank-pin.

The parts when adjusted in position should be so proportioned that thesplit box or clamping-block should lack just a little of coming up tothe collar on the pin, so that it Will not strike and prevent aneffective clamping action on the shank.

Practice has demonstrated that the crankpin mounted in the Wheel inaccordance with the present invention Will be absolutely rigid, and bysetting up the nuts with even a slight pressure it is clamped so firmlyas to preclude all possibility of its being Wrenched or turned in itsbearing under the action of the connecting-rod, although, as anadditional protection against its being turned, it is preferable thatthe securing-threads be so cut that any turning of the crank-pin Willtend to draw the nuts more tightly into place when the locomotive isrunning forward.

While I have specifically described my invention as applied to alocomotiveJ drive- Wheel, it Will be understood that the invention isequally applicable to any crank or other machinery Where it is desiredto secure a crank-pin in place.

i IIaving thus described 1n y invention, what I claim as new isl. Thecombination With the crank or Wheel having a conical aperture formedtherein, of

a crank-pin seating against the crank or Wheel at the smaller end of theaperture, conical clamping-blocks iitted in said aperture and having acentral bore fitting the shank of the crank-pin and a locking-nut on therear end of the crank-pin bearing against the larger end of theclamping-blocks; substantially as described.

2. The combination with the crank or Wheel having a conical apertureformed therein, and a sectional clamping-block having its outer surfaceiitted to the conical aperture and a cylindrical internal aperture, acrank-pin having a collar seating against the crank or Wheel at thesmaller end of the aperture and a cylindrical shank extending throughthe aperture in the sectional ciampi 11g-block and a locking-nutscrewing on the rear end of the crank-pin and coperating with thesectional clamping-block to hold the parts in adjusted position;substantially as described.

3. The combination with the crank or wheel having the conical aperturetherein and the crank-pin seating against the crank or Wheel at thesmaller end of the aperture and having the shank projecting through saidaperture, of the split clamping-block surrounding said shank and havingthe external conical surface tting the aperture and central enlargedrecess at the rear end and the locking-nut screwing on the shank of thecrank-pin and seating in said recess; substantially as described.

ROBERT BRAGG. lVitnesses:

CHARLES J. MCKEE, WVM. F. GHAMBERLIN.

